Conventionally, the interior materials for design of automobile parts did not occupy a larger proportion than the other parts, but as consumers' desires gradually become different and the design and function of automobile are differentiated, research and development of film materials for automobile interior materials are going on.
In recent years, as the needs for imparting simple decorations and tactile properties as well as improving the decorations and designs of automobile interior film materials have been increased, the decorating method has been applied with expansion to the three-dimensional surface and the vacuum thermoforming method is employed for applying decoration sheets to the injection molding. In this case, it is necessary to study the adhesive layer which can be attached to the interior material with flexibility in molding by controlling the reactivity of the functional group in compliance with the high temperature and high pressure condition so that the decoration sheet fuses well in the interior material.